Hillcrest FSM-6 250hz firmware and Carmacks Sensor fusion

[Namielus]

Hi!

I was searching around to find any threads that describe how to utilize Carmacks sensor fusion from the Doom3 BFG open source files.
Hillcrest provided me with a link to the 250hz software, but explained that Carmack took raw data from the IMU and
did the sensor fusion in software rather than on-chip fusion.

My question is if anyone has the exact code that carmack used for sensor fusion, or know about a thread I failed to find that details how to do it.

Also, does FreePie add any latency if I use that as the main interface to my game? Wider input support would be good, since each input device does not have to be manually added.

CyberVillain, we are located in Norway. I was wondering, given your expertise on FreePie - maybe we could hire you as an advisor to get ready before GDC?
If you are interested we can talk more in PM, and I can tell you more about our projects.

[Fredz]

I don't know the specific algorithm John Carmack used for sensor fusion in Doom 3, but you may have a try with this algorithm :
http://www.x-io.co.uk/open-source-imu-a ... lgorithms/

It's been used in the PS Move API and by several people here also.

[Namielus]

Thanks fredz, I am going to take a look at the ps move API also, loved your video.

[CyberVillain]

Carmacks fusion is not included in the Doom 3 BFG source so I do not know what fusion he is doing.
The current FreePIE implementation uses the built in fusion of the Hillcrest lib. I havent looked at the Freespace lib (Brantlew did that plugin for FreePIE) but if it exposes the raw data of the sensors then you can use the Mahony fusion that we have in FreePIE to fuse the raw data, I dont know if this gives any better results then just using the fusion code provided by the freespace lib.

FreePIE always output at around 60hz, this is not as bad as it sounds, for example, my Android plugin samples raw data at about 200-250 hz and then processed that using the Mahony fusion, the higher sample rate increases the accuracy and produces a much better result even when you just output at 60hz

Other than limiting to 60hz output FreePIE does not add any lag.

I would gladly help you, just PM me the details and I'll get back to you

[zalo]

I think Carmack mentioned he was using algorithms from Armadillo Aerospace.

I'm not sure if he's at liberty to release stuff like that.